reply: How much leaf for PCR?

[Robert F. Whittier]

In response to Ulrich Melcher's question on the amount of leaf 
tissue to use in preparing DNA for PCR:

	We routinely obtain 500 ng to 1 ug of DNA from two leaves 
(about 20 mg) of fresh Arabidopsis tissue.  Since we use 10 ng of 
DNA in a 20 ul PCR reaction for single copy sequences, a 100 ul 
reaction could certainly be run with the DNA obtained from less 
than a mg of tissue.  If you want to standardize the amount of 
leaf tissue used without weighing it, you might try using the lid 
of  a microfuge tube to punch out a disc of leaf tissue into  the 
tube,  as  suggested by Edwards et al (1991)  Nucleic  Acids  
Research, Vol 19, p. 1349.

Bob Whittier
Mitsui Plant Biotechnology Research Institute